The present invention relates generally to a film used to add the appearance of a texture to a surface of a model, and a method to produce such a film.
For certain products where design is an important feature, and in particular for larger, more expensive products, a clay model of the proposed design may be made before finalizing the design for production. This model may be full scale so designers and other decision makers at the manufacturer can view the design from every angle and determine if the shape and features are acceptable. Such a process is used, for example, when redesigning an automotive vehicle. For such a model, great pains are taken to assure the accuracy of every detail of the model since the preparation to manufacture such a vehicle may cost hundreds of millions of dollars.
One area that is sometimes neglected on such a model is the surface texture for surfaces that will not be smooth on the actual product. For example, on a vehicle, the sheet metal has a smooth surface, so the clay can be sculpted smooth. But for some components, such as, for example, interior components like seats, instrument panels and door panels, the actual product may have a particular surface texture. It may be important for visualizing the complete aesthetic appearance of the component or vehicle that these simulated components in the model have the appropriate texture and color. Thus, the ability to accurately represent an intended texture in clay is important in order to allow interior stylists and others to assess the appearance of modeled prototype interiors in a coherent and consistent fashion.
It is imperative that any attempt to add texture to surfaces of the clay model does not compromise the shape and surface features of that modeled component. However, due to the fragility of the clay surface, this can be difficult. Applying too much pressure at any point may deform the clay, thus compromising the shape of the model. Moreover, there may be creases and complex curvature on the model where a surface texture is desired, making the addition of surface texture in those areas difficult.
A rolled-grain (i.e., texturing) technique has been employed in the past where an object with the desired texture is rolled over the clay surface. However, such a technique has tended to limit the range of textures for which it can be applied, and the level of detail. Moreover, it can be difficult to apply the texture around creases and in areas with complex curvature.
Another technique for applying a surface texture employs heat-formable rigid plastic material that has a surface texture molded into it. But this technique generally requires application to a harder modeling material than clay, so it is used later in a vehicle development process when hard models cut out of wood or a similar hard materials are available. This delays the timing for determining desired surface textures later in the development process than is desired, and is much more expensive than is desired. In addition, since the materials available are relatively rigid, even after proper preparation, there is a necessity for an extensive amount of cutting, trimming, and fitting in order to completely cover a complex surface.
Yet another technique being explored is applying plastic films that have surface textures molded into them. While some of these show promise, they generally have several significant drawbacks. They are relatively difficult and very expensive to manufacture, and some may employ undesirable volatile organic chemical (VOC) compounds in their manufacture. In addition, many lack the desired strength, flexibility, shelf-life, texture retention, and/or shrink resistance desired in a texturing layer. And the color selection is more involved than is desired since these plastic films generally require very specific surface preparation for color coating.